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प्रश्न
When the positive charge on an ion increases or the negative charge on them decreases it is called as _______.
विकल्प
reduction
corrosion
oxidation
decomposition
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उत्तर
When the positive charge on an ion increases or the negative charge on them decreases it is called as oxidation.
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संबंधित प्रश्न
What is an oxidising agent?
A shiny brown-coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black-colored compound formed.
What is meant by rust?
Identify the component oxidised in the following reaction:
H2S + Cl2 → S + 2HCl
Is oxidation an exothermic or an endothermic reaction?
Give one example of an oxidation-reduction reaction which is also a combination reaction.
Explain reduction in terms of gain or loss of oxygen with one example.
When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and (ii) substance reduced.
In the reaction represented by the following equation:
CuO (s) + H2 (g) → Cu (s) + H2O (1)
(a) name the substance oxidised
(b) name the substance reduced
(c) name the oxidising agent
(d) name the reducing agent
In the context of redox reactions, the removal of hydrogen from a substance is known as:
(a) oxidation
(b) dehydration
(c) reduction
(d) dehydrogenation
Fill in the blank
In redox reaction oxidation and reduction occur ............................
Define reduction.
Define redox reaction.
TRUE \ FALSE
Hydrogen is a good oxidizing agent.
How would you change a metal like Cu into its ions?
The colours of aqueous solutions of CuSO4 and FeSO4 as observed in the laboratory are:
(A) pale green and light blue respectively
(B) light blue and dark green respectively
(C) dark blue and dark green respectively
(D) dark blue and pale green respectively
Identify from the following reaction the reactants that undergo oxidation and reduction.
\[\ce{2Ag2O → 4 Ag + O2 \uparrow}\]
Compare hydrogen with alkali metals on the basis of:
Oxide formation
Give the general group study of hydrogen with reference to
burning
Why this reaction is considered a reversible reaction?
Why zinc and aluminium are considered to have a unique nature. Give balanced equations to support your answer.
Is it essential that oxidation and reduction must occur side by side in a chemical reaction? Explain
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
H2S + Cl2→ 2HCl + S
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
Cl2 + H2S → 2HCl + S
State whether the following conversion is oxidation or reduction:
K → K+ + e-
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Pb2+→ Pb + Zn 2+
Divide the following reactions into oxidation and reduction half-reaction:
Cl2 + 2Br- → Br2 + 2Cl-
A metal oxide that is reduced by hydrogen is
Choose terms from the options given in brackets to complete this sentence.
When CuO reacts with hydrogen,………………… is reduced and ……………….is oxidized to ………………….
(CuO, H2, Cu, H2O)
Name:
a substance that oxidizes concentrated HCl to chlorine.
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
Name:
a gas that is oxidizing as well as a reducing agent.
Complete and balance the following equation:
\[\ce{K + H2O -> }\]________+ ________
Complete and balance the following equation:
Fe + H2O →___________+____________
With reference to oxidation & reduction reaction – complete the statement given by filling in the blanks with only the words (a) Addition (b) Removal.
‘Oxidation is a chemical reaction involving ____ of oxygen to a substance or ____ of hydrogen from a substance. Reduction on the otherhand involves ____ of hydrogen to a substance or ____ of oxygen from a substance.
Explain the term oxidation in term of addition and removal of oxygen/hydrogen with a suitable example.
Explain the term reduction in term of addition and removal of oxygen/hydrogen with a suitable example.
State what is oxidising agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
Give two test for an oxidising agent.
Explain the following reaction with their balanced chemical equation.
Hydrogen sulphide reacts with sulphur dioxide.
Oxidation is a process which involves ____________.
Identify the oxidising agent (oxidant) in the following reactions
`2"Mg" + "O"_2 -> 2"MgO"`
Identify the oxidising agent (oxidant) in the following reactions
`3"Fe" + 4"H"_2"O" -> "Fe"_3"O"_4 + 4"H"_2`
Which among the following are physical or chemical change?
Evaporation of petrol
Which among the following are physical or chemical change?
Curding of milk
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
Some bubbles of a gas are seen when lead (Pb) is reacted with the acid.
Explain this observation giving suitable reason.
On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained :
- Write a balanced chemical equation for the reaction involved.
- What other name can be given to this precipitation reaction?
- On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?
You are provided with two containers made up of copper and aluminium. You are also provided with solutions of dilute HCl, dilute HNO3, ZnCl2 and water. In which of the above containers, can these solutions be kept?
The tarnishing of metals is an example of ______ reaction.
Choose the odd one out and write the reason:
Identify the following reactions as oxidation/reduction/redox reaction
Zn + CuSO4 → Cu + ZnSO4
Identify the following reactions as oxidation/reduction/redox reaction
CuO+H2 → Cu+H2O
What is rancidity?
Find the oxidation number of the element in the following compound.
Zn in ZnSO4
Find the oxidation number of the element in the following compound.
Ca in CaH2
State whether the given chemical reaction is a redox reaction or not. Justify your answer.
\[\ce{MnO_2 + 4HCl->MnCl_2 +2H_2O + Cl_2}\]
The metallic oxide which can be reduced by using common reducing agents is ______.
